Abstract: Provided is an optical device. The optical device includes a substrate having a waveguide region and a mounting region, a planar lightwave circuit (PLC) waveguide including a lower-clad layer and an upper-clad layer on the waveguide region of the substrate and a platform core between the lower-clad layer and the upper-clad layer, a terrace defined by etching the lower-clad layer on the mounting region of the substrate, the terrace including an interlocking part, an optical active chip mounted on the mounting region of the substrate, the optical active chip including a chip core therein, and a chip alignment mark disposed on a mounting surface of the optical active chip. The optical active chip is aligned by interlocking between the interlocking part of the terrace and the chip alignment mark of the optical active chip and mounted on the mounting region.

Abstract: Provided is an optical module. The optical module includes: an optical bench having a first trench of a first depth and a second trench of a second depth that is lower than the first depth; a lens in the first trench of the optical bench; at least one semiconductor chip in the second trench of the optical bench; and a flexible printed circuit board covering an upper surface of the optical bench except for the first and second trenches, wherein the optical bench is a metal optical bench or a silicon optical bench.

Abstract: Provided is an optical module. The optical module includes: an optical bench having a first trench of a first depth and a second trench of a second depth that is lower than the first depth; a lens in the first trench of the optical bench; at least one semiconductor chip in the second trench of the optical bench; and a flexible printed circuit board covering an upper surface of the optical bench except for the first and second trenches, wherein the optical bench is a metal optical bench or a silicon optical bench.

Abstract: A contactless thickness measuring apparatus is provided which includes an terahertz transmitter configured to receive the first optical path signal from the coupler and to generate a terahertz continuous wave using the first optical signal and an applied bias; an optical delay line configured to delay the second optical path signal output from the coupler; and an terahertz receiver configured to receive the terahertz continuous wave penetrating a sample and to detect an optical current using the terahertz continuous wave and the second optical path signal delayed. A thickness of the sample is a value corresponding to the optical current which phase value becomes a constant regardless of a plurality of measurement frequencies.

Abstract: Disclosed herein is a photomixer and method of manufacturing the photomixer which can fundamentally solve the existing restrictive factors of a PCA and a photomixer which are core parts of a conventional broadband terahertz spectroscopy system. The presented photomixer includes an active layer formed on a top surface of a substrate, the active layer being formed on an area on which light is incident, and a thermal conductive layer formed on the top surface of the substrate, the thermal conductive layer being formed on an area other than the area on which light is incident. The active layer is formed to have a mesa cross section, and the thermal conductive layer is regrown on an area other than the area on which light is incident using an MOCVD method, and has a flattened surface.

Abstract: Provided is an optical module. The optical module includes: an optical bench having a first trench of a first depth and a second trench of a second depth that is lower than the first depth; a lens in the first trench of the optical bench; at least one semiconductor chip in the second trench of the optical bench; and a flexible printed circuit board covering an upper surface of the optical bench except for the first and second trenches, wherein the optical bench is a metal optical bench or a silicon optical bench.

Abstract: Provided is a broadband photomixer technology that is a core to generate continuous frequency variable and pulsed terahertz waves. It is possible to enhance light absorptance by applying the transmittance characteristic of a 2D light crystal structure and it is possible to increase the generation efficiency of terahertz waves accordingly. Moreover, it is possible to implement a wide area array type terahertz photomixer by applying an interdigit structure and spatially properly arranging a light crystal structure having various cycles. Accordingly, it is possible to solve difficulty in thermal characteristic and light alignment by mitigating the high light density of a light absorption unit and low photoelectric conversion efficiency is drastically improved. In addition, the radiation pattern of terahertz waves may be electrically controlled through the present invention.

Abstract: Provided is a terahertz wave generating/detecting apparatus and a method for manufacturing the same. The terahertz wave generating/detecting apparatus includes; a substrate having an active region and a transmitting region; a lower metal layer extending in a first direction on the active region and the transmitting region of the substrate; a graphene layer disposed on the lower metal layer on the active region; and upper metal layers extending in the first direction on the graphene layer of the active region and the substrate in the transmission region, wherein a terahertz wave is generated or amplified by a surface plasmon polariton that is induced on a boundary surface between the graphene layer and the lower metal layer by beated laser light applied to the graphene layer and the metal layer.

Abstract: Provided is an optical module. The optical module includes: an optical bench having a first trench of a first depth and a second trench of a second depth that is lower than the first depth; a lens in the first trench of the optical bench; at least one semiconductor chip in the second trench of the optical bench; and a flexible printed circuit board covering an upper surface of the optical bench except for the first and second trenches, wherein the optical bench is a metal optical bench or a silicon optical bench.

Abstract: Disclosed is a rectifier capable of performing a high speed rectifying operation, and includes: a first semiconductor layer; a second semiconductor layer; and a third semiconductor layer, in which the first semiconductor layer and the third semiconductor layer are formed of semiconductor layers having the same type, and the second semiconductor layer is formed between the first semiconductor layer and the third semiconductor layer, is formed of a semiconductor layer having a different type from that of the first semiconductor layer and the third semiconductor layer, and is formed in graded doped state.

Abstract: A terahertz wave generating module includes a bidirectional light source which provides a first dual-mode beam in a first direction and a second dual-mode beam in a second direction; a forward lens unit which focuses the first dual-mode beam; a photomixer unit which converts the first dual-mode beam focused by the forward lens unit into a terahertz wave; a backward lens unit which focuses the second dual-mode beam; and a light output unit which uses the second dual-mode beam focused by the backward lens unit as a light signal, wherein the bidirectional light source, the forward lens unit, the photomixer unit, the backward lens unit, and the light output unit are integrated in a housing.

Abstract: Disclosed is a photomixer for generating and detecting a terahertz continuous wave, including: an optical conductor to which beating light is incident; and a plurality of antenna feeding electrodes formed on both side surfaces of the optical conductor, and configured to receive a current of a terahertz frequency.

Abstract: Provided herein is terahertz continuous wave emitting device having: a plurality of laser light sources generating a plurality of laser lights; and an absorption area formed between the plurality of laser light sources in order to adjust interaction of the plurality of laser lights, wherein the absorption area is configured to have a photo diode, an antenna integrated into the photo diode.

Abstract: Provided is an optical device. The optical device includes a substrate having a waveguide region and a mounting region, a planar lightwave circuit (PLC) waveguide including a lower-clad layer d an upper-clad layer on the waveguide region of the substrate and a platform core between the lower-clad layer and the upper-clad layer, a terrace defined by etching the lower-clad layer on the mounting region of the substrate, the terrace including an interlocking part, an optical active chip mounted on the mounting region of the substrate, the optical active chip including a chip core therein, and a chip alignment mark disposed on a mounting surface of the optical active chip. The optical active chip is aligned by interlocking between the interlocking part of the terrace and the chip alignment mark of the optical active chip and mounted on the mounting region.

Abstract: Provided are a THz-wave generation/detection module and a device including the same, which increase heating efficiency and are miniaturized. The module includes a photomixer chip, a lens, a PCB, and a package. The photomixer chip includes an active layer, an antenna, and a plurality of electrode pads. The lens is disposed on the photomixer chip. The PCB includes a plurality of solder balls connected to the electrode pads, under the photomixer chip. The package surrounds a bottom and side of the PCB, and dissipates heating of the active layer, which is transferred from the electrode pad of the photomixer chip to the PCB, to outside.

Abstract: Provided is an optical module. The optical module includes: an optical bench having a first trench of a first depth and a second trench of a second depth that is lower than the first depth; a lens in the first trench of the optical bench; at least one semiconductor chip in the second trench of the optical bench; and a flexible printed circuit board covering an upper surface of the optical bench except for the first and second trenches, wherein the optical bench is a metal optical bench or a silicon optical bench.

Abstract: Provided is an optical device. The optical device includes a substrate having a waveguide region and a mounting region, a planar lightwave circuit (PLC) waveguide including a lower-clad layer and an upper-clad layer on the waveguide region of the substrate and a platform core between the lower-clad layer and the upper-clad layer, a terrace defined by etching the lower-clad layer on the mounting region of the substrate, the terrace including an interlocking part, an optical active chip mounted on the mounting region of the substrate, the optical active chip including a chip core therein, and a chip alignment mark disposed on a mounting surface of the optical active chip. The optical active chip is aligned by interlocking between the interlocking part of the terrace and the chip alignment mark of the optical active chip and mounted on the mounting region.

Abstract: Provided is a broadband photomixer technology that is a core to generate continuous frequency variable and pulsed terahertz waves. It is possible to enhance light absorptance by applying the transmittance characteristic of a 2D light crystal structure and it is possible to increase the generation efficiency of terahertz waves accordingly. Moreover, it is possible to implement a wide area array type terahertz photomixer by applying an interdigit structure and spatially properly arranging a light crystal structure having various cycles. Accordingly, it is possible to solve difficulty in thermal characteristic and light alignment by mitigating the high light density of a light absorption unit and low photoelectric conversion efficiency is drastically improved. In addition, the radiation pattern of terahertz waves may be electrically controlled through the present invention.

Abstract: Provided are a dual mode semiconductor laser and a terahertz wave apparatus using the same. The dual mode semiconductor laser includes a distributed feedback laser structure section including a first diffraction grating on a substrate and a distributed Bragg reflector laser structure section including a second diffraction grating on the substrate. A first wavelength oscillated by the distributed feedback laser structure section and a second wavelength oscillated by the distributed Bragg reflector laser structure section are different from each other, and the distributed feedback laser structure section and the distributed Bragg reflector laser structure section share the same gain medium with each other.

Abstract: An optical device may include first and second lasers generating first and second laser beams; and a photo detector detecting the first and second laser beams. The optical detector comprises a substrate, a first impurity layer on the substrate, an absorption layer on the first impurity layer and a second impurity layer on the absorption layer. The absorption layer generates a terahertz by a beating of the first and second laser beams and has a thickness of less than 0.2 ?m.